Film wrapping machines for wrapping products, articles, packages, or the like, in wrapping film conventionally comprise a film roll upon which a supply of the wrapping film is disposed, and a plurality of rollers around which the wrapping film is routed so as to have a predetermined amount of tension developed within the film such that the wrapping film exhibits a predetermined or requisite amount of tension required for the film wrapping operation. It was noted within U.S. Pat. No. 5,862,647, which issued to Scherer et al. on Jan. 26, 1999, that one type of film wrapping stretch head conventionally comprises a set of rollers having upper and lower end portions thereof respectively mounted within upper and lower frame members whereby, in order to route the wrapping film from the film supply roll, through the various tensioning and idler rollers, and to the palletized load, such as, for example, during a film supply roll exchange or replenishment operation of a new or fresh film supply roll for a depleted film supply roll, a leading end of the wrapping film must be withdrawn from the film supply roll and manually routed or threaded through and around the set of tension rollers.
It was further noted that this process was awkward, difficult, tedious, and time-consuming to perform by operator personnel because the film must be threaded or routed beneath the upper frame member and between the tension rollers, It was noted still further that in order to improve upon the aforenoted stretch head and its film threading system, other stretch head systems have been disclosed, for example, within U.S. Pat. No. 4,914,891which issued to Suolahti on Apr. 10, 1990, as well as within U.S. Pat. No. 5,414,979 which issued to Moore et al. on May 16, 1995, whereby the various rollers are mounted in an interdigitated manner upon frame members which are movably mounted in a pivotal manner with respect to each other between, in effect, OPENED and CLOSED positions. While such pivotal frame stretch head systems therefore rendered the film threading or routing process easier to perform, the film threading or routing process attendant such stretch head systems were nevertheless time-consuming and therefore resulted in a significant amount of operational downtime attendant a film roll replacement, exchange, or replenishment operation.
In order to therefore improve still further upon the PRIOR ART systems, the stretch head system disclosed within the aforenoted U.S. Pat. No. 5,862,647 which issued to Scherer et al. on Jan. 26, 1999, was developed wherein, in effect, the upper frame member of the stretch head was effectively eliminated such that the wrapping film routing or threading operation could be readily and easily accomplished in a relatively simple manner by enabling the insertion of the wrapping film, into the spaces defined between the tension rollers, in an axial direction parallel to the axes of the tension rollers. More particularly, the operating or driving system for the stretch rollers or tension rolls is provided within a first end or bottom region of the stretch head, and second or upper ends of the tension rolls or stretch rollers are mounted or secured within independent support or mounting brackets. In this manner, the second ends of the tension rolls or stretch rollers are not connected to each other, the second ends of the tension rolls or stretch rollers are spaced from each other so as to permit the wrapping film to be threaded or routed therebetween, and the second end of the stretch head is effectively open so as to permit the wrapping film to be easily, quickly, and simply inserted in an axial mode between the tension rolls or stretch rollers. As a result, the awkward, difficult, and tedious threading or routing of the wrapping film beneath the upper frame member and between the stretch rollers or tension rolls, in a direction which is substantially transverse to the longitudinal axes of the stretch rollers or tension rolls, is effectively obviated. In addition, the structure and relative arrangement of the operative components of such a stretch head effectively eliminated the need for mounting the tension rolls or stretch rollers upon frame members which were pivotally movable between CLOSED and OPENED positions in order to effect, for example, a supply film roll exchange, replacement, or replenishment operation.
While the aforenoted improved stretch head has met operational specifications and expectations in that, for example, the insertion or routing of the wrapping film between the tension rolls or stretch rollers has in fact been rendered easier, quicker, and simpler to perform and achieve, and therefore, the improved stretch head has in fact been commercially successful, it has been experienced that in connection with, for example, the wrapping of palletized loads, it is not always possible to dispose the leading or free end portion of the wrapping film at a proper or predetermined angular position, and at an elevational level, with respect to the palletized load so as to enable the wrapping film to effectively be disposed around the lowermost regions of the palletized load. This wrapping technique of the wrapping film with respect to the palletized load is critically important in that when the wrapping film is able to be wrapped around the lowermost regions of the palletized loads, whereby in effect, the wrapping film is in fact wrapped around the lowermost extent of the palletized load per se as well as partially around the support pallet, then the palletized load will in fact be able to be properly fixedly secured upon the support pallet. Still further, it is also important that the final roller component, around which the wrapping film is routed and which is located just upstream from the palletized load as considered in the dispensing direction of the wrapping film from the supply film roll toward the palletized load, can properly secure and control the disposition or orientation of the wrapping film such that the wrapping film is in fact dispensed toward the palletized load at a proper or predetermined disposition or orientation whereby the wrapping film will be properly wrapped upon the palletized load in order to ensure the fixation of the load upon the support pallet in a stabilized manner.
A need therefore exists in the art for a new and improved stretch head wherein the leading or free end portion of the wrapping film can be disposed at a proper or predetermined angular position, and at an elevational level, with respect to the palletized load so as to enable the wrapping film to effectively be disposed around the lowermost regions of the palletized load, and wherein the disposition or orientation of the wrapping film can be positioned or controlled with respect to the stretch head such that the wrapping film can be dispensed toward the palletized load at a proper or predetermined disposition or orientation whereby the wrapping film can in fact be properly wrapped upon the palletized load so as to ensure proper and secure fixation of the palletized load upon the support pallet in a stabilized manner.